The administration of systems consists in the execution of operations for maintaining the operating systems, the network and the data of data processing system. These operations may comprise backup of the operating systems on the computers, reorganization and validity checking of storage for user data.
These maintenance operations are started with commands entered from the operator console locally attached to the computer. These operations are performed by the system administrator on site, when no user application is started and when the network is not active. Usually the maintenance of a data processing system is performed during the weekends, when the system and the network are unused.
Thus, there is a need for having the maintenance operations performed in unattended mode without the presence of the system administrator on site.
As with the IBM AS/400 (AS/400 is a trademark of IBM Corporation in certain countries), some systems have a possibility to delay the commands for maintenance operations on the operating system: mainly these operations concern backup of systems on hard disks. Unfortunately, the maximum delay time may be not sufficient to postpone the execution from one day to two days later. This restriction prevents a system administrator to delay on Friday the execution of system maintenance for the next Sunday morning. As a matter of fact this is a facility that the companies selling services to IBM AS/400 users, for instance, would like to offer. The system backup command provided in the operating system of the IBM AS/400 is the GO SAVE command accepting a time parameter limited to 24 hours. This means that if today, Friday, at 12:00 am we start a GO SAVE command with a delay hour of 1:00 p.m., the backup operation will start at 1:00 p.m. this same day Friday and not the next day because starting at 1:00 the next day would use a delay of more than 24 hours.
Moreover, to execute the maintenance operations on a data processing systems, the operating systems have to enter a special ‘sleeping state’ preventing them from any outside interference which could damage their integrity. Particularly, maintenance operations on the IBM AS/400 server, are executed when the system is in ‘restricted state’. If a problem occurs during the execution of the unattended operations during the weekend, the operating systems need to be restored to their operational mode, user applications and networks need to be restarted for Monday morning.
This is why the first objective of the invention is to provide a method for delaying to the coming days maintenance operations of systems which do not offer this facility.
It is a second objective of the invention to have a method allowing the maintenance operations to be performed in a secure way for the availability of the data processing system which have to go back to operational mode.